FIG. 6.

Inhibition of the ternary TBP-TFIIA-DNA complex by polyamide 3. (A) DNase I footprint of U−2 DNA in the presence of DNA alone (lane 2); TBP (lane 3); TBP plus TFIIA (lane 4); TBP, TFIIA, and polyamide 3 at 3, 10, 15, 20, 30, and 50 nM (lanes 5 to 10, respectively). All reaction components were incubated simultaneously for 30 min prior to digestion with DNase. Lane 1, G+A sequencing ladder; lane 11, 50 nM polyomide 3, no TBP or TFIIA. The location of the TATA box and polyamide-binding site are indicated. (B) Graphical representation of inhibition plotted as the fraction of DNA bound (normalized to the fraction of TBP bound in the absence of polyamide) versus polyamide concentration.